#!/usr/bin/env python3
# Copyright (c) 2008-9 Qtrac Ltd. All rights reserved.
# This program or module is free software: you can redistribute it and/or
# modify it under the terms of the GNU General Public License as published
# by the Free Software Foundation, either version 2 of the License, or
# version 3 of the License, or (at your option) any later version. It is
# provided for educational purposes and is distributed in the hope that
# it will be useful, but WITHOUT ANY WARRANTY; without even the implied
# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
# the GNU General Public License for more details.

import platform
import sys



from PyQt4.QtCore import (QSize, QString, QVariant, Qt, SIGNAL)
from PyQt4.QtGui import (QAction, QApplication, QColor, QFont,
        QFontMetrics, QIcon, QKeySequence, QMenu, QPixmap,
        QTextCharFormat, QTextEdit)


class RichTextLineEdit(QTextEdit):

    (Bold, Italic, Underline, StrikeOut, Monospaced, Sans, Serif,
     NoSuperOrSubscript, Subscript, Superscript) = range(10)


    def __init__(self, parent=None):
        super(RichTextLineEdit, self).__init__(parent)

        self.monofamily = QString("courier")
        self.sansfamily = QString("helvetica")
        self.seriffamily = QString("times")
        self.setLineWrapMode(QTextEdit.NoWrap)
        self.setTabChangesFocus(True)
        self.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
        self.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
        fm = QFontMetrics(self.font())
        h = int(fm.height() * (1.4 if platform.system() == "Windows"
                                   else 1.2))
        self.setMinimumHeight(h)
        self.setMaximumHeight(int(h * 1.2))
        self.setToolTip("Press <b>Ctrl+M</b> for the text effects "
                "menu and <b>Ctrl+K</b> for the color menu")

    
    def toggleItalic(self):
        self.setFontItalic(not self.fontItalic())


    def toggleUnderline(self):
        self.setFontUnderline(not self.fontUnderline())


    def toggleBold(self):
        self.setFontWeight(QFont.Normal
                if self.fontWeight() > QFont.Normal else QFont.Bold)


    def sizeHint(self):
        return QSize(self.document().idealWidth() + 5,
                     self.maximumHeight())


    def minimumSizeHint(self):
        fm = QFontMetrics(self.font())
        return QSize(fm.width("WWWW"), self.minimumHeight())


    def contextMenuEvent(self, event):
        self.textEffectMenu()

        
    def keyPressEvent(self, event):
        if event.modifiers() & Qt.ControlModifier:
            handled = False
            if event.key() == Qt.Key_B:
                self.toggleBold()
                handled = True
            elif event.key() == Qt.Key_I:
                self.toggleItalic()
                handled = True
            elif event.key() == Qt.Key_K:
                self.colorMenu()
                handled = True
            elif event.key() == Qt.Key_M:
                self.textEffectMenu()
                handled = True
            elif event.key() == Qt.Key_U:
                self.toggleUnderline()
                handled = True
            if handled:
                event.accept()
                return
        if event.key() in (Qt.Key_Enter, Qt.Key_Return):
            self.emit(SIGNAL("returnPressed()"))
            event.accept()
        else:
            QTextEdit.keyPressEvent(self, event)


    def colorMenu(self):
        pixmap = QPixmap(22, 22)
        menu = QMenu("Colour")
        for text, color in (
                ("&Black", Qt.black),
                ("B&lue", Qt.blue),
                ("Dark Bl&ue", Qt.darkBlue),
                ("&Cyan", Qt.cyan),
                ("Dar&k Cyan", Qt.darkCyan),
                ("&Green", Qt.green),
                ("Dark Gr&een", Qt.darkGreen),
                ("M&agenta", Qt.magenta),
                ("Dark Mage&nta", Qt.darkMagenta),
                ("&Red", Qt.red),
                ("&Dark Red", Qt.darkRed)):
            color = QColor(color)
            pixmap.fill(color)
            action = menu.addAction(QIcon(pixmap), text, self.setColor)
            action.setData(QVariant(color))
        self.ensureCursorVisible()
        menu.exec_(self.viewport().mapToGlobal(
                   self.cursorRect().center()))


    def setColor(self):
        action = self.sender()
        if action is not None and isinstance(action, QAction):
            color = QColor(action.data())
            if color.isValid():
                self.setTextColor(color)


    def textEffectMenu(self):
        format = self.currentCharFormat()
        menu = QMenu("Text Effect")
        for text, shortcut, data, checked in (
                ("&Bold", "Ctrl+B", RichTextLineEdit.Bold,
                 self.fontWeight() > QFont.Normal),
                ("&Italic", "Ctrl+I", RichTextLineEdit.Italic,
                 self.fontItalic()),
                ("Strike &out", None, RichTextLineEdit.StrikeOut,
                 format.fontStrikeOut()),
                ("&Underline", "Ctrl+U", RichTextLineEdit.Underline,
                 self.fontUnderline()),
                ("&Monospaced", None, RichTextLineEdit.Monospaced,
                 format.fontFamily() == self.monofamily),
                ("&Serifed", None, RichTextLineEdit.Serif,
                 format.fontFamily() == self.seriffamily),
                ("S&ans Serif", None, RichTextLineEdit.Sans,
                 format.fontFamily() == self.sansfamily),
                ("&No super or subscript", None,
                 RichTextLineEdit.NoSuperOrSubscript,
                 format.verticalAlignment() ==
                 QTextCharFormat.AlignNormal),
                ("Su&perscript", None, RichTextLineEdit.Superscript,
                 format.verticalAlignment() ==
                 QTextCharFormat.AlignSuperScript),
                ("Subs&cript", None, RichTextLineEdit.Subscript,
                 format.verticalAlignment() ==
                 QTextCharFormat.AlignSubScript)):
            action = menu.addAction(text, self.setTextEffect)
            if shortcut is not None:
                action.setShortcut(QKeySequence(shortcut))
            action.setData(QVariant(data))
            action.setCheckable(True)
            action.setChecked(checked)
        self.ensureCursorVisible()
        menu.exec_(self.viewport().mapToGlobal(
                   self.cursorRect().center()))


    def setTextEffect(self):
        action = self.sender()
        if action is not None and isinstance(action, QAction):
            what = action.data().toInt()[0]
            if what == RichTextLineEdit.Bold:
                self.toggleBold()
                return
            if what == RichTextLineEdit.Italic:
                self.toggleItalic()
                return
            if what == RichTextLineEdit.Underline:
                self.toggleUnderline()
                return
            format = self.currentCharFormat()
            if what == RichTextLineEdit.Monospaced:
                format.setFontFamily(self.monofamily)
            elif what == RichTextLineEdit.Serif:
                format.setFontFamily(self.seriffamily)
            elif what == RichTextLineEdit.Sans:
                format.setFontFamily(self.sansfamily)
            if what == RichTextLineEdit.StrikeOut:
                format.setFontStrikeOut(not format.fontStrikeOut())
            if what == RichTextLineEdit.NoSuperOrSubscript:
                format.setVerticalAlignment(
                        QTextCharFormat.AlignNormal)
            elif what == RichTextLineEdit.Superscript:
                format.setVerticalAlignment(
                        QTextCharFormat.AlignSuperScript)
            elif what == RichTextLineEdit.Subscript:
                format.setVerticalAlignment(
                        QTextCharFormat.AlignSubScript)
            self.mergeCurrentCharFormat(format)


    def toSimpleHtml(self):
        html = QString()
        black = QColor(Qt.black)
        block = self.document().begin()
        while block.isValid():
            iterator = block.begin()
            while iterator != block.end():
                fragment = iterator.fragment()
                if fragment.isValid():
                    format = fragment.charFormat()
                    family = format.fontFamily()
                    color = format.foreground().color()
                    text = Qt.escape(fragment.text())
                    if (format.verticalAlignment() ==
                        QTextCharFormat.AlignSubScript):
                        text = QString("<sub>%1</sub>").arg(text)
                    elif (format.verticalAlignment() ==
                          QTextCharFormat.AlignSuperScript):
                        text = QString("<sup>%1</sup>").arg(text)
                    if format.fontUnderline():
                        text = QString("<u>%1</u>").arg(text)
                    if format.fontItalic():
                        text = QString("<i>%1</i>").arg(text)
                    if format.fontWeight() > QFont.Normal:
                        text = QString("<b>%1</b>").arg(text)
                    if format.fontStrikeOut():
                        text = QString("<s>%1</s>").arg(text)
                    if color != black or not family.isEmpty():
                        attribs = ""
                        if color != black:
                            attribs += ' color="{0}"'.format(color.name())
                        if not family.isEmpty():
                            attribs += ' face="{0}"'.format(family)
                        text = (QString("<font%1>%2</font>")
                                .arg(attribs).arg(text))
                    html += text
                iterator += 1
            block = block.next()
        return html


if __name__ == "__main__":
    app = QApplication(sys.argv)
    lineedit = RichTextLineEdit()
    lineedit.show()
    lineedit.setWindowTitle("RichTextEdit")
    app.exec_()
    print(str(lineedit.toHtml()))
    print(str(lineedit.toPlainText()))
    print(str(lineedit.toSimpleHtml()))


